Reply To: Prevent terms order being overwritten when updating post

i activate this hook so i can modify wordpress post_tag sort parameter to true:

function postTag_sort_tags() {
    global $wp_taxonomies;
    $wp_taxonomies['post_tag']->sort = true;
}
add_action( 'init', 'postTag_sort_tags' );

do you have any idea how to set it back to false after checking some condition? i've tried it but it seems init hooks is too early to get the post ID which in this case i need it for the condition.